Con Coughlin is the Telegraph's Defence Editor and a world-renowned expert on global security and terrorism issues. He is the author of several critically acclaimed books. His new book, Churchill's First War: Young Winston and the fight against the Taliban, is published by Macmillan in London and Thomas Dunne Books in New York. He appears regularly on radio and television in Britain and America.

Obama is preparing to abandon Afghanistan to its fate

Don't be fooled. When President Obama says that America is preparing for the total withdrawal of all American forces from Afghanistan by the end of this year, what he really means is that he has already decided on the total withdrawal of all American forces from Afghanistan by the end of this year.

The White House can blame Hamid Karzai, the country's recalcitrant president, all it wants for the current stalemate between Kabul and Washington over the proposed Bilateral Security Agreement (BSA), under which the US and other Nato states would continue to provide military and other assistance to the newly-established Afghan security forces once Nato combat operations officially draw to a close at the end of 2014.

Although a Loya Jirga of 2,500 Afghan tribal elders voted in favour of a joint security agreement with the US at the end of last year, Mr Karzai has held off putting pen to paper on the grounds that it should only be ratified once a new presidence has been elected in the forthcoming Afghan presidential poll, which is scheduled to be held in April.

But the real reason Mr Karzai is refusing to play ball is that he feels a deep sense of betrayal with the Obama administration, which he believes – quite rightly in my view – has reneged on its promise to stabilise the country before withdrawing its forces.

As Robert Gates, the former US Defence Secretary has made abundantly clear in his recent memoir, the President long ago lost faith in his own strategy for resolving the Afghan issue, and instead opted for the politically expedient option of cut and run.

But while this policy might win him political plaudits among his Left-wing followers, it is hardly likely to result in Afghanistan becoming the kind of stable country which will no longer be a haven for Islamist terrorists.

Nor has Mr Obama's abandonment of the Afghan cause been lost on Mr Karzai who, having once enjoyed weekly telephone conversations with the White House when President George W. Bush was still in office, now has little if any contact with the Oval Office, as I discovered when I visited Washington earlier this month.

The upshot is that, rather than working with Mr Obama, Mr Karzai seems to be doing his level best to irritate the president by staging various stunts, such as his recent decision to release a number of suspected Taliban prisoners in the face of strong US objections.

Mr Obama can complain all he wants about the Afghan president's capricious behaviour. But if you turn your back on a once-valued ally, then what else do you expect?